Tape slitting tool



April 7, 1970 SLOBODA ET AL 3,504,435

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United States Patent s,se4,43s TAPE SLITTING TDGL George Sloboda, 6018 N. Maplewood, and Michael Keller, 6025 N. Maplewood, both of Chicago, Ill. 60645 Filed Mar. 18, 1968, Ser. No. 713,586 Int. Cl. B261) 29/02 US. Cl. 3t)293 9 Claims ABSTRACT OF THE DISCLOSURE There is disclosed a tape slitting tool comprising a pair of guide arms positioned substantially at right angles to each other, each of the guide arms having an inner edge and an outer edge, the juncture of the inner edges of the guide arms defining a longitudinally extending guide edge, the guide edge having a slot therein adjacent one end thereof and bisecting the angle between the guide arms. A cutting member having a cutting edge and a support section is disposed in the slot in the guide edge so that the cutting member is supported by the guide arms with the cutting edge thereof extending outwardly from the guide edge to engage the tape material to be slit. Each of said guide arms carries a depressible guide bar thereon disposed substantially adjacent to the outer edge of the guide arm and extending longitudinally of the guide arm, whereby said tool is arrangeable in confronting relation with two taped surfaces that define a corner with the guide edge in juxtaposition with the longitudinal axis of the corner for guiding longitudinal movement therealong and the guide bars engaging the adjacent taped surfaces to accommodate variations in the angle between the two taped surfaces as the tool is advanced longitudinally, the guide bars serving to accurately maintain the cutting edge of the cutting member in the appropriate slitting position relative to the tape material. Handle means is carried by the guide arms for manually manipulating the tool.

This invention relates to a tape slitting tool for slitting wall board tap-e along a corner between adjacent walls or between a wall and a ceiling of a room.

In new building construction, particularly the construction of high-rise buildings, wallboard is used for the room side walls, the ceiling of the room normally being formed of concrete. Because the upper edge of the wallboard may vary in height relative to the ceiling, it is customary to apply a seam tape to close the corner formed by the inner edge of the wallboard and the ceiling so as to provide a uniform appearance. The tape is normally applied with about one half of its width on the side wall and the other half on the ceiling. After the taping procedure has been completed, it has been found necessary to cut the two halves of the tape at the juncture between the wall and ceiling because otherwise, as the building settles the tape is torn in a ragged fashion. Present methods using a hand held knife have been found to be very time consuming and inaccurate.

Accordingly, it is a primary object of the invention to provide a tape slitting tool for slitting the seam tape applied to the corner formed between a side wall and the ceiling, the tool effecting slitting of the tape in a quick manner and with great accuracy.

It is a further object of the invention to provide a tape slitting tool having movable or depressible guide bars thereon so that upon moving the slitting tool longitudinally along the adjacent corner between the wall and the ceiling, the guide bars accommodate any variance in angle etween the wall and the ceiling, thereby increasing the accuracy of the slitting element of the tool as the tool is moved along this juncture.

Yet another object of the invention is to provide a tape slitting tool of the character described which is further provided with releasable handle means in the form of a ball joint, the handle means permitting great freedom of movement of the user relative to the tool while maintaining the tool in its proper operative position relative to the wall and ceiling.

In accordance with one aspect of the invention there is provided a tape slitting tool comprising a pair of guide arms positioned substantially at right angles to each other, each of the guide arms having an inner edge and an outer edge, the juncture of the inner edges of the guide arms defining a longitudinally extending guide edge. The guide edge has a slot therein adjacent one end thereof and bisecting the angle between the guide arms. A cutting member having a cutting edge and a support section is disposed in the slot in the guide edge so that the cutting member is supported by the guide arms with the cutting edge thereof extending outwardly from the guide edge to engage the tape material to be slit. Each of the guide arms carries a depressible guide bar thereon disposed substantially adjacent to the outer edge of the guide arm and extending longitudinally of the guide arm, whereby the tool is arrangeable in confronting relation with two taped surfaces that define a corner with the guide edge in juxtaposition with the longitudinal axis of the corner for guiding longitudinal movement therealong with the guide bars engaging the adjacent taped surfaces to accommodate variations in the angle between the two taped surfaces as the tool is advanced longitudinally, the guide bars serving to accurately maintain the cutting edge of the cutting member in the appropriate slitting position relative to the tape material. Handle means is carried by the guide arms for manually manipulating the tool.

Further features of the invention pertain to the particular arrangement of the elements of the tape slitting tool whereby the above outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing, in which:

FIGURE 1 is a perspective view illustrating the tape cutting tool of the invention as used in slitting the seam tape disposed on the corner formed at the juncture of a wall and ceiling;

FIG. 2 is a plan view of the tape cutting tool illustrated in FIG. 1;

FIG. 3 is an end view of the tape cutting tool illustrated in FIG. 2, with sections thereof broken away and illustrating elements thereof in greater detail;

FIG. 4 is a bottom view of the tape cutting tool illustrated in FIGS. 1 and 2;

FIG. 5 is an end view of the tape cutting tool taken in the direction of the arrows along the line 5-5 of FIG. 3; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 3, illustrating the cutting element of the tape cutting tool in greater detail.

Referring now to the drawing and more particularly to FIG. 1 thereof, there is illustrated a tape cutting tool designated generally as 10, the tape cutting tool being disposed to slit two taped surfaces 11 and 12 which are reectively secured to the juncture between a wall 13 and the adjacent ceiling 14. The tool 10 is adapted to move along the longitudinal axis of the corner 15 formed by the juncture of the wall 13 and the ceiling 14 and to accomplish this in an accurate manner, the tool 10 includes a rigid body member 20, the body member 20 preferably being comprised of a metallic material and having integrally formed guide arms 20 and 21 positioned at substantially right angles to each other.

In the embodiment illustrated, the guide arms 20 and 21 are each generally identical in shape and each is provided with an outer edge 23, a trailing edge 24, a leading edge 25, an outer surface 26 and an inner surface 27. The inner edges of the arms cooperate to define a longitudinally extending guide edge 28 (FIG. 6) which is adapted to be disposed along the longitudinal line of intersection of the corner formed by the wall 13 and the ceiling 14. As illustrated in FIG. 3, the arms 21 and 22 are preferably disposed so that the outer surfaces meet at an angle of slightly less than 90, and more particularly, at an angle of about 88, for reasons hereafter explained. The upper surface of each arm is also provided with a shoulder portion 29 at the outer edge thereof.

The guide edge 28 of the block 20 is provided with a slot 30 therein (FIGS. 3 and 6), the slot 30 bisecting the included angle formed by the arms 21 and 22. An angle bar 31 overlies the guide edge 28 and the arms thereof are respectively secured to the adjacent guide arms 21 and 22 by a pair of flat head screws 32. The angle bar 31 has a first slot 33 therein which overlies the slot 30 formed in the guide edge 28. The angle bar 31 is slightly longer than the block 20 and includes a portion which extends beyond the leading edge 25 of the block. The leading edge of the angle bar 31 is provided with a slot 34 therein whereby the leading edge 35 of the angle bar 33 may be directed downwardly away from the peak of the angle bar, thereby to facilitate sliding movement of the block 20 along the corner line 15. The angle bar 31 is preferably made of a highly wear resistent material such as steel, thereby to impart long life to the guide surface of the tape slitting tool The aligned slots 30 and 33 in the block and the angle bar are provided to received a cutting member designated generally as 40 therein, the cutting member being provided with a cutting edge 41 on one side thereof and a support section 42 which is received within the aligned slots 30 and 33. A cover plate 43 is positioned over the lead edges 24 of the block at the intersection of the arms thereof and overlies the slot 30 therein, whereby the cover plate 43 prevents outward movement of the cutting member 40 when the cutting edge 41 thereof engages the tape material to be slit. The cover plate is held in position by a pair of screws 44.

As best seen in FIG. 6, the lower end of the slot 30 is provided with an enlarged threaded opening 45 within which is disposed a set screw 46, the set screw being accessible from the bottom of the tool as seen in FIGS. 1 and 4. The height of the cutting edge 41 of the cutting member may be adjusted relative to the guide edge 28 by appropriate rotation of the set screw 46, the lower edge of the support surface 42 of the cutting member being disposed in the slot 30 so that it abuts the upper end of the set screw 46.

To lock the. cutting member 40 in position and to pro vide for the quick removal and replacement thereof, the arm 22 has a threaded opening 47 therethrough which intersects the slot 30, a set screw 48 being disposed within the opening 47 for lateral engagement with the support section 42 of the cutting member as illustrated by the dashed lines in FIG. 6. It will be appreciated that the cutting member 40 easily may be removed by releasing the locking force applied thereto by the set screw 48.

In accordance with the invention, guide means is provided for the block to assure the accuracy of movement of the cutting member as the tool 10' is advanced longitudinally along the corner, regardless of minor variations in the angle between the wall and ceiling. To accomplish this, each arm 21 and 22 of the tool 10 is provided with a longitudinally extending depressible guide bar 50.

As best seen in FIG. 3, each guide bar 50 includes a pair of inclined outer surfaces 51 joined by a generally planar central surface 52. Each guide bar 50 is held in position by a pair of shoulder screws 53 disposed substantially adjacent to the opposite ends of the bar 50 and received in openings 54 therein, the shoulder screws extending through suitable openings 55 provided adjacent to the outer edge 23 of each arm and extending through the shoulder portion 29 of each of the arms 21 and 22. Each of the shoulder screws 53 includes a cylindrical shank or shaft 56 which terminates in a threaded end 57, the threaded end 57 being received in the threaded openings 54 in the guide bar 50. The threaded end 57 is intended to be substantially equal in length to the depth of the openings 54 so that the shoulder screw does not extend beyond the planar portion 52 of the guide bar.

With continued reference to FIG. 3, it will be seen that the openings 55 in the arms are countersunk over the greatest portion thereof to provide a cylindrical chamber around the shank 56 of the associated shoulder screw, a compression spring 58 being disposed about the shank 56 of the shoulder screw 53 within the cylindrical chamber formed by the countersunk opening. The upper end of the compression spring 58 engages the lower surface of the guide bar 58, while the lower end of the spring abuts against the portion of the arm at the head of the opening 55, the spring 58 normally biasing the guide bar 50 away from the outer surface of the respective one of the arms 21 and 22. Each guide bar 50 is approximately equal in height to the depth of the shoulder 29 in each arm whereby each bar may be depressed until the central planar surface 52 thereof is coplanar with the outer surface 26 of the associated arm. As noted, the outer surfaces 26 are preferably disposed at an angle of about 88, whereby the tool can be used even though the corner formed between the wall and the ceiling is also slightly less than As the tool 10 is advanced along the juncture of the wall and ceiling 13 and 14 respectively, the guide bars 50 are depressible to accommodate variations in the angle between the wall and the ceiling, whereby the tool 10 may be firmly pressed against the wall and ceiling so that the guide edge 28 thereof firmly seats in the corner line 15, thereby insuring that the cutting member 40 thereof will follow an accurate line as the tool advances along the corner.

The tool 10 is provided with a handle securing member designated generally as 60, whereby the tool may be easily manipulated by the user thereof. As best seen in FIGS. 1, 5 and 6, the handle securing member 60 includes a ball joint type member 61 having a ball 62 at one end thereof and a threaded shaft portion 63 at the opposite end thereof, the threaded shaft being provided to receive an elongated handle such as 64, the handle 64 being provided with an internally threaded recess (not shown) in the end thereof.

The ball 62 is disposed within an elongated hemispherical recess 65 provided in the block 20, whereby the shaft portion 63 thereof is free to move relative to the block 20. To increase the area of movement, a channel 65A is provided along the inner surfaces of the guide arms, the channel 65A having cylindrical cut-outs 65B therein adjacent the recess 65.

The ball joint member 61 is held in position by the arms of a generally U-shaped spring 66, the arms 67 of the spring being received in a pair of parallel slots 68 provided in the guide arms 21 and 22. The arms 67 of the spring 66 are provided with outwardly turned ends 69 which engage the inner surface of the slots 68. When the spring is urged through the slots 68, the inner surfaces thereof engage the ends 69 and cause the arms 67 to engage the upper section of the ball 62, thereby to prevent outward movement of the ball from the recess 65. One of the slots 68 is provided with a threaded opening therein which is adapted to receive a screw 70, the head of which prevents outward movement of the arm of the spring.

If it is desired to remove the ball 62 from its recess in the block, it is merely necessary to remove the screw 70 and slide the spring 66 forwardly, until the enlarged U-shaped end thereof surrounds the ball 62 as illustrated by the full lines in FIG. 5, whereupon the ball may be removed from within the recess 65.

In operation, the user merely places the tool in engagement with the ceiling and wall, the ceiling usually being of concrete, and then advances the tool longitudinally along the corner line to slit the seam tape from one end of the room to the other, and so on around the room. The slit made will be hardly visible but will permit the settling of the wall without causing the tape to split in a ragged fashion. Because of the guide bars 50, it is possible to accurately slit the tape material regardless of minor variations in angle between the wall and the ceiling.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall Within the true spirit and scope of the invention.

What is claimed is:

1. A tape slitting tool comprising, a pair of guide arms positioned substantially at right angles to each other, each of said guide arms having an inner edge and an outer edge, the juncture of said inner edges of said guide arms defining a longitudinally extending guide edge, said guide edge having a slot therein adjacent one end thereof and bisecting the angle between said guide arms, a cutting member having a cutting edge and a support section, said support section being disposed in said slot in said guide edge so that said cutting member is supported by said guide arms with the cutting edge thereof extending outwardly from said guide edge to engage the tape material to be slit, each of said guide arms carrying a depressible guide bar thereon disposed substantially adjacent to the outer edge of said guide arm and extending longitudinally of said guide arm, whereby said tool is arrangeable in confronting relation with two taped surfaces that define a corner with said guide edge in juxtaposition with the longitudinal axis of the corner for guiding longitudinal movement therealong with said guide bars engaging the adjacent taped surfaces to accommodate variations in the angle between the two taped surfaces as the tool is advanced longitudinally, said guide bars serving to accurately maintain the cutting edge of said cutting member in the appropriate slitting position relative to the tape material, and handle means carried by said guide arms for manually manipulating said tool.

2. The tape slitting tool set forth in claim 1, wherein said guide arms are rigidly interconnected.

3. The tape slitting tool set forth in claim 1, wherein said guide arms are integrally formed of a unitary metallic material.

4. The tape slitting tool set forth in claim 1, wherein each of said guide arms has a pair of longitudinally spaced openings therethrough disposed substantially adjacent to the outer edge thereof, each of said guide bars comprises a longitudinally extending member having a pair of shafts rigidly secured thereto substantially adjacent the respective opposite ends thereof, said shafts being received by the respective openings in the adjacent guide arm, and spring means disposed about each of said shafts between said guide arm and said guide bar for normally biasing each of said guide bars away from the corresponding guide arm.

5. The tape slitting tool set forth in claim 1, and further comprising means for releasably retaining said handle means on said guide arms.

6. The tape slitting tool set forth in claim 1, wherein said handle means carried by said guide arms comprises a ball joint member including a ball carried by said guide arms, said ball having a shaft extending outwardly therefrom, the outer end of said shaft being threaded to receive an associated elongated handle.

7. The tape slitting tool set forth in claim 6', and further comprising a generally U-shaped spring for releasably retaining said handle means on said guide arms, each of said guide arms having a longitudinally extending slot therein for receiving the arms of said spring.

8. The tape slitting tool set forth in claim 1, and further comprising an angle bar secured to said guide arms and overlying said guide edge, said angle bar providing a wearing surface for said guide edge.

9. The tape slitting tool set forth in claim 1, and further comprising means for adjustably positioning said cutting member relative to said guide edge.

References Cited UNITED STATES PATENTS 2,038,884 4/1936 Chalmer 30-294 X 3,349,486 10/1967 Voight 30294 3,382,579 5/1968 Prater 30294 ROBERT C. RIORDAN, Primary Examiner I. C. PETERS, Assistant Examiner US. Cl. X.R. 30-294 

